Smith Graham, Wermuth Urs D
Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
Acta Crystallogr C. 2013 May;69(Pt 5):538-43. doi: 10.1107/S0108270113009487. Epub 2013 Apr 13.
The structures of the anhydrous proton-transfer compounds of the sulfa drug sulfamethazine with 5-nitrosalicylic acid and picric acid, namely 2-(4-aminobenzenesulfonamido)-4,6-dimethylpyrimidinium 2-hydroxy-5-nitrobenzoate, C12H15N4O2S(+)·C7H4NO4(-), (I), and 2-(4-aminobenzenesulfonamido)-4,6-dimethylpyrimidinium 2,4,6-trinitrophenolate, C12H15N4O2S(+)·C6H2N3O7(-), (II), respectively, have been determined. In the asymmetric unit of (I), there are two independent but conformationally similar cation-anion heterodimer pairs which are formed through duplex intermolecular N(+)-H···O(carboxylate) and N-H···O(carboxylate) hydrogen-bond pairs, giving a cyclic motif [graph set R2(2)(8)]. These heterodimers form separate and different non-associated substructures through aniline N-H···O hydrogen bonds, one one-dimensional, involving carboxylate O-atom acceptors, the other two-dimensional, involving both carboxylate and hydroxy O-atom acceptors. The overall two-dimensional structure is stabilized by π-π interactions between the pyrimidinium ring and the 5-nitrosalicylate ring in both heterodimers [minimum ring-centroid separation = 3.4580 (8) Å]. For picrate (II), the cation-anion interaction involves a slightly asymmetric chelating N-H···O R2(1)(6) hydrogen-bonding association with the phenolate O atom, together with peripheral conjoint R1(2)(6) interactions between the same N-H groups and O atoms of the ortho-related nitro groups. An inter-unit amine N-H···O(sulfone) hydrogen bond gives one-dimensional chains which extend along a and inter-associate through π-π interactions between the pyrimidinium rings [centroid-centroid separation = 3.4752 (9) Å]. The two structures reported here now bring to a total of four the crystallographically characterized examples of proton-transfer salts of sulfamethazine with strong organic acids.
已确定磺胺类药物磺胺二甲嘧啶与5-亚硝基水杨酸和苦味酸形成的无水质子转移化合物的结构，即2-(4-氨基苯磺酰胺基)-4,6-二甲基嘧啶鎓2-羟基-5-硝基苯甲酸盐，C12H15N4O2S(+)·C7H4NO4(-)，(I)，以及2-(4-氨基苯磺酰胺基)-4,6-二甲基嘧啶鎓2,4,6-三硝基苯酚盐，C12H15N4O2S(+)·C6H2N3O7(-)，(II)。在(I)的不对称单元中，有两个独立但构象相似的阳离子-阴离子异二聚体对，它们通过双分子N(+)-H···O(羧酸盐)和N-H···O(羧酸盐)氢键对形成，形成一个环状基序[图集R2(2)(8)]。这些异二聚体通过苯胺N-H···O氢键形成单独且不同的非缔合子结构，一个是一维的，涉及羧酸盐O原子受体，另一个是二维的，涉及羧酸盐和羟基O原子受体。在两个异二聚体中，嘧啶鎓环和5-亚硝基水杨酸盐环之间的π-π相互作用使整体二维结构得以稳定[最小环中心间距 = 3.4580 (8) Å]。对于苦味酸盐(II)，阳离子-阴离子相互作用涉及与酚盐O原子的略微不对称螯合N-H···O R2(1)(6)氢键缔合，以及相同N-H基团与邻位相关硝基的O原子之间的外围共轭R1(2)(6)相互作用。单元间胺N-H···O(砜)氢键形成沿a方向延伸的一维链，并通过嘧啶鎓环之间的π-π相互作用相互缔合[质心-质心间距 = 3.4752 (9) Å]。此处报道的这两种结构使磺胺二甲嘧啶与强有机酸形成的质子转移盐的晶体学表征实例总数达到四个。
